Edit Window and Mix Window Keyboard Shortcuts : Zoom

Zoom
 
Zoom to show entire session horizontally without affecting vertical zoom or scrolling
Zoom in horizontally on a selection without affecting vertical zoom or scrolling
Vertical zoom to show all notes (lowest to highest) in MIDI and Instrument (MIDI)
Continuously zoom vertically on a single audio track (or group of tracks)
Control+drag with the Zoomer tool up or down in the track
Start-drag with the Zoomer tool up or down in the track
Control+Shift+drag in an audio track with the Zoomer tool
Start+Shift-drag in an audio track with the Zoomer tool
Command+Option+[ or Command+Option+]
View entire session and reset waveform display to the default height
Set all audio track waveform heights to match the waveform height of the top-most audio track in the Edit window
Hold down Command key while dragging the Zoomer tool
Hold down Ctrl key while dragging Zoomer tool
Option-click on any Horizontal Zoom In or Out button, or Audio or MIDI Zoom In or Out button
Alt-click on any Horizontal Zoom In or Out button, or Audio or MIDI Zoom In or Out button
Maximum zoom before waveform drawn from disk (faster drawing from RAM)
Control+Zoom preset number (1, 2, 3, 4, or 5 on computer keyboard),
or Zoom preset number (1, 2, 3, 4, or 5 on computer keyboard, in Commands Keyboard Focus)
Start+Zoom preset number (1, 2, 3, 4, or 5 on computer keyboard),
or Zoom preset number (1, 2, 3, 4, or 5 on computer keyboard in Commands Keyboard Focus)
Command-click Zoom preset number in Mix Window toolbar
Ctrl-click Zoom preset number in Mix Window toolbar